<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Bootstrap button</title>
    <link href="https://cdn.bootcss.com/twitter-bootstrap/4.4.1/css/bootstrap.min.css" rel="stylesheet">
    <style>
        body {
            display: flex;align-items: center;flex-direction: column;justify-content: center;
        }
        p {
            width: 80%;
            display: flex;
            justify-content: space-between;
        }
        h3 {
            margin: 6px 0;
        }
        button {
            width: 10em;
        }
        a {
            width: 10em;
        }
        input {
            width: 10em;
        }
    </style>
</head>
<body>
    <h3>Buttons</h3>
    <p>
        <button type="button" class="btn btn-primary">Primary</button>
        <button type="button" class="btn btn-secondary">Secondary</button>
        <button type="button" class="btn btn-success">Success</button>
    </p>
    <p>
        <button type="button" class="btn btn-danger">Danger</button>
        <button type="button" class="btn btn-info">Info</button>
        <button type="button" class="btn btn-warning">Warning</button>
    </p>
    <p>
        <button type="button" class="btn btn-light">Light</button>
        <button type="button" class="btn btn-link">Link</button>
        <button type="button" class="btn btn-dark">Dark</button>
    </p>
    <h3>A Tag</h3>
    <p>
        <a type="button" class="btn btn-primary">Primary</a>
        <a type="button" class="btn btn-secondary">Secondary</a>
        <a type="button" class="btn btn-success">Success</a>
    </p>
    <h3>Input Tag</h3>
    <p>
        <input type="button" class="btn btn-primary" value="Primary"/>
        <input type="button" class="btn btn-secondary" value="Secondary"/>
        <input type="button" class="btn btn-success" value="Success"/>
    </p>
    <h3>Outline buttons</h3>
    <p>
        <button type="button" class="btn btn-outline-primary">Primary</button>
        <button type="button" class="btn btn-outline-secondary">Secondary</button>
        <button type="button" class="btn btn-outline-success">Success</button>
    </p>
    <p>
        <button type="button" class="btn btn-outline-danger">Danger</button>
        <button type="button" class="btn btn-outline-info">Info</button>
        <button type="button" class="btn btn-outline-warning">Warning</button>
    </p>
    <p>
        <button type="button" class="btn btn-outline-light">Light</button>
        <button type="button" class="btn btn-outline-dark">Dark</button>
    </p>
    <h3>Other Size Buttons</h3>
    <p>
        <button type="button" class="btn btn-primary btn-lg">Primary</button>
        <button type="button" class="btn btn-secondary btn-lg">Secondary</button>
        <button type="button" class="btn btn-success btn-lg">Success</button>
    </p>
    <p>
        <button type="button" class="btn btn-primary btn-sm">Primary</button>
        <button type="button" class="btn btn-secondary btn-sm">Secondary</button>
        <button type="button" class="btn btn-success btn-sm">Success</button>
    </p>
    <h3>Block level Buttons</h3>
    <p>
        <button type="button" class="btn btn-primary btn-block">Primary</button>
    </p>
        
</body>
</html>